RS4 Engine start button on S3

MarcQuinlivan said:
Interesting that the service manager is offering to do that for you. Presumably that will be warrantied by them since they are doing the work?

You might ask him how it was done when he's finished. Did he quote you a price?
Click to expand...

Yeah, rather leave them with the issue should one arise.

He hasn't quoted me but reckon should be roughly 2-3hrs labour cost.
 
I do like these service managers as most talk complete ******** with no real knowledge of cars especially electrics, lol, but you never know he could be right, but I do fear its not that easy, see if I can prove myself wrong though, but would love to see that guy wire it in himself, unlikely.

Anyway update is I have got a relay for starting the car, only to find out that its a 40amp fuse inline with the starter motor so have to get a larger relay as mine is only 30, it would work as a test relay anyway, but once I've found the start wire all I have to do is clamp that in a circuit with the relay & start button & thats it all done.

The fuse for starter motor is under the hood on fuse block left side of engine compartment number F15 for mine & no doubt others, ignition will turn on but when turned over wont do squat, I just hope its not a can signal from barrel to starter motor as then gonna have to go into engine bay for wiring, joyyyyyyy

I wont get my clamp meter until mid next week, as I'm bored today I'm gonna try & hunt it down with my old meter as I am fed up with the trims all loose lol, would be nice for at least 1 day to have car all back together, update you when done.

But when fitting relay I know its a stupid thing to remind but dont forget to fuse the circuit as switching 40amps better safe than sorry huh.
 
Ok for the update of the day, it looks like it could be CAN switched guys as I have taken all the steering modules etc parts of & the barrel actually connects to the steering main control module by a very short fly lead with several very thin wires not enough to switch 40 amps thats for sure, also the control module has very thin wires & a thicker earth/power feed wires that IMHO would never be thick enough to switch 40amps, it would burn the cable for sure, so it looks like its engine bay wiring, god here we go, as the starter motor is fused in the bay I dont think we can tag onto anything in the fusebox on drivers side panel in car, further investigation needed for sure.

Rabbit IMHO I would cancel the job for now mate as I can see it becoming extremely expensive mate, unless you're happy to pay them hours on hours, its not a simple wiring job thats for sure, hold of for few days so we can do some tracing of wiring mate.

Ah hold on I just had a brainwave

urmmmmm................................................

Ok as its switched via the ignition, I wonder if it just powers up one of the wires on the barrel as the barrel has 6 wires connected to it, now CAN would be 1-2 so why do we have 6 wires????

So I wonder if barrel when starting powers up one wire which then makes a relay in the engine bay trigger the ignition, would we be able to connect in parallel on these wires to power the starter.

Urrrm...........................................................

Ok I will do some more wiring traces, get back to you guys later, ***** about to rain

Watch this space
 
Ok people, doing some continuity testing, more good news is the barrel at different positions of the key actually creates a circuit on 4-5 different wires but not all at same time, creates circuits when key inserted, when key turned to position 1, when key turned back to start position & also when key is removed completely, this would explain why we have power to certain items on the car at certain positions of the key, like radio, lights etc.

But importantly when the key is inserted & fully turned to start the car it creates a circuit on an additional wire which is RED, this wire/circuit is only on when the key is fully turned to start the car, no other time is that circuit created, this to me suggests this is the start wire for the signal to the starter motor relay or ecu.

Now I will do some voltage & current testing & update you later.

I will actually remove that wire from the harness & plug all back in & see what it does to car when that wire is disconnected only.

Whooooppppppeeeeeeeeeeeeeeeeeeeeeeeeeeeee, lol, lol.
 
Happy days Nigel!

Just one quick question about the red wire. You say it only has power when the key is fully turned to start the car. What about when the engine is already running and you turn the key fully?
 
Just a thought on the starter wiring. I'm sure you have it under control, but just one quick point.

Presumably when the key is turned all the way it is closing a contact (or whatever the correct terminology is) to send a live current from one side to the other and back to the starter relay. What I'm getting at is that there is always live (whether it be fixed or switched) coming to a point in the barrel, and then when you turn the key all the way you allow that signal to pass back down the red wire to the starter relay.

Would taking those two wires and connecting them to pins 4 and 6 on the start button give the desired effect?
 
yeah baby bring it on, I've cracked it & starts like a ****** dream.

Wired in temp to test, no need for a large relay, Rabbit it is just 2 wires on back of the barrel, but it wasnt as easy as they put it trust me, alot of checking wiring, circuits & voltages for sure, to be honest Rabbit I would do it yourself & save a bundle of money for sure.

All it needs is a 11-12 volt supply switched on the red wire to start the car, you can pick up the ignition switched 12 volts on another of the 6 wires on the barrel, so just run a speaker type thin wire to the button, one to supply the 12v & the other to connect to the red wire to make the circuit, so when pressed it then puts the 12v on the red wire & hey presto starts like a dream.

You do have to turn key to 1st position but apart from that it works perfectly, I might wire in a fuse/diode on the wires to protect the car but otherwise thats it, would need to remove the wheel, the control module & unplug rear plugs to get into the wires & as there's small room underneath would need soldering I think as my scotch locks are to big.

Control module has a certain way of coming of, PM me for my number Marc & I will happily advise any info.

When got more time I will try best to write something up on this or as I've done legwork maybe Marc can, lol, lol.

All I have to do is confirm the 12v supply wire colour to you as I used a temp feed from spare ashtray cable unused which lights the button at night when lights turned on.

As I always say nothings impossible.
 
Yes, when engine running & you turn key to start car position it does have voltage on the red wire, so when car is running already it stops the start voltage from causing the horrible starter motor noise when engine started already, would say the circuitry in starter motor is designed to not allow the voltage threw if engine is running.
 
Ok, last but least, the 12v ignition switched wire to use from the rear of the barrel is the yellow wire.

So all you do is wire in parallel the 12v supply onto the yellow wire from rear of barrel, send this down the wire to the start button, then return the start button back on the 2nd wire to the barrel & wire in parallel to the red wire, thus when pressing button creates the circuit exactly the same as the key does when turned fully to start car.

I will check the current when I get my clamp meter then wire a fuse inline to protect the circuit, better safe than sorry.

I havnt fully wired in permanently yet but on test as loose wires works every single time, no problems at all, will test for few days then will put all back properly.

But as far as I'm concerned as they say thats a wrap
 
Ok anyone suggest a new mod before I get bored, lol, lol.
 
Good work Nigel.

Is there a need to hook it up at the barrel end? Is it not possible to make the circuit lower down the steering column where there might be a bit more space?

Is it still possible to use the key to start the car, and have you tried pressing the button while the engine is running to see if it replicates the functionality of the ignition key?

Also, it there a method to removing the wheel to get at the bits?
 
I'm hopefully going to get to this on Monday next (Bank Holiday over here), so I'll document all the steps with photos and stick up a post to save you doing it Nigel since you already have all the bits installed.

I wouldn't mind a few photos of the connections you've made at the barrel so I can see what it is you've done and how the wires are routed.

What amp fuse would you think would be needed to put inline between the button and the car? I'd say it would be best to put a fuse between the yellow wire and the button and the button and the red wire.

Does it matter which wire connects to which pins 4 and 6 on the button?
 
God you wanna know my inside leg size aswell, lol, kidding.

Ok you have to connect to the small 3 inch long fly lead that goes from end of barrel into another plug that plugs into top of module, basically its positioned underneath the barrel/on top of the control module, its the little fly lead that is covered up when the module is clipped back into position, thats why its a more than likely solder job as no room for clip on.

Key still works 100% due the fact we are wiring it in parallel with existing circuit, not in series fella.

Replicates key exactly so no continued starting to motor, as my previous post said mate, starter motor circuitry stops that from trying to power starter motor like in older cars, so no horrible noise.

Method would be, remove airbag with 2 rear bolts which may/may not be covered by little plastic covers, disconnect the loom carefully, the big clip use your 2 small fingers either side to pull the yellow clip forward to release from the slip ring, importantly make a mark on the steering wheel & the column thread for centering of wheel when replacing but it might already have been done as mine was, then undo the wheel with the multi grooved torx style socket, its well on there so some force required, remove wheel but whatever you do, dont move the slip ring, when wheel removed tape with masking tape the inner ring to the outer ring case of the slip ring so it cant move, this is important dont forget, then remove the upper trim by lifting up on steering wheel end to unclip from the lower part, then the part by the DIS slides forward then comes out all as one, the lower trim has 2 torx bolts at front, obvious that part, then underneath you must remove the steering wheel poistioning lock handle so u can take the lower trim of, there is also 1 torx bolt under the lower trim to remove, then she's of, rest u know how to I think.
 
Well just taken for test drive which cleared the steering light & the esp light, all I have to do now is clear my airbag error & she's done.

I will look at a diode & fuse inline but have to check make sure its only a single use wire & isnt reversing polarity on any of those 2 wires, very much doubt but on this mod better safe than sorry.
 
Yeah, the last thing you want is to be stuck somewhere unable to start the car. That's one of the reasons I'd be keen to have the button working in parallel with the key so if something goes wrong with the button the key can still be used to start the engine.

I've seen some chaps who fitted the Honda S2000 button and they just took the pins from the barrel.

I assume you have VAGCOM for clearing the airbag error.

Did you need to disconnect the battery prior to doing the wiring, or did you just do it as a precautionary measure? (I assume you disconnected the battery as that is usually why the steering and esp lights are on.)
 
Didnt disconnect battery at all mate.

Yeah got hex can usb.

Nah light came up mate cause I turned ignition on when cables/module wernt plugged in at times which then brings up lights, but they cleared on test & airbag as we all know is purely error needs clearing for that to go away.

Apart from me actually tracking & testing wires etc for all you guys its a ****** simple install to be honest, just the initial tracing wires out & testing is the bar steward, but another one bites the dust.

Ok, now parking sensors & S3 kit maybe, you got parking sensors, if so do they mute radio etc & show you in DIS anything or just beeps from rear of car & radio remains running?

Cause audi do the after market version which is the ridiculously expensive same one as you get on fleabay for £30 but they charge £200, I thought the proper CAN version was fully integrated into car on factory installed so mutes radio etc.
 
Dont you think me should plant a new thread to advise wiring sorted as this one is so ****** long no one would read past the 2nd page, lol, lol.
 
Whatever you reckon. If you want to leave it until I get my step by step guide done next week that might be a better idea - save any other silly questions like my ones above and requests for photos!
 
audi upgrades
Spot on dude, await the guide as my brains fried from wiring, lol.
 
Is there a way to:

1- press the keyfob to unlock the car
2- start the car with the button without inserting the key?

Seems a bit pointless otherwise, you may aswell just turn the key hehe.
 
the key needs to be in the ignition for the immobiliser to deactivate. I saw a guy who decided to butcher his key and tape it to the steering column so it was in proximity to the sensor, but that meant that anybody who wanted to steal his car only had to open the door and push the start button.

The Touareg has a keyless go system that has a seperate control unit under the dash, but I doubt you'd be able to get that to work with the A3. The Mercedes and Bentley systems also allow keyless start, but obviously they are much more expensive which is why the RS4 one requires the key in the ignition.

Might seem like a pointless mod without that functionality, but each to their own I suppose. It is a relatively cheap mod and adds a bit of a novelty factor to it.
 
well there are ways to do this but I'm not gonna look at that mod just yet as I have already thought that one through a little, as the ignition switches on the electrical field for the immobiliser chip in the top of the key, the key or chip would have to be near to that ignition to be able to start the car anyway

now you can take the chip out of the key & easily install it next to the barrel, but then someone can easily nick your car cant they, also you have to turn the key to the 1st position anyway to turn on the electrics to a certain degree for a number of things on the car not just the ignition, I have an idea to get round this but I wont divulge this info at the moment until tested, so there are lots of variables to consider, of which I am still thinking of a way to do that allows my car to be fully security wise protected aswell as being able to lose the key neccessity.

I'll work with Marc & Matt on this I think, what yer think Marc?

For me I already bought the RS4 button for my S4 B6 avant, but as I sold that one it was spare so thought why not try to fit to the A3, so I have.

Pointless, well thats matter of opinion fella, I like it even if someone else doesnt, it was a challenge to me to do so learnt even more about wiring while doing it, so I look at it in 2 ways, cool mod & also taught me something about audi ignition wiring aswell as the countless others that will do this mod no doubt now knowing it can be done.
 
Perhaps if the press of the unlock on your fob also knocked off the immobiliser too then it would be wicked ;)

I.e. You only get to start the engine if you used the key unlock the doors :)
 
Fella, not being funny, but you dont seem to hear what I'm saying, you cant knock the immobiliser of as it is triggered by the chip in the top of the key, so no you cant do this without the key being near the barrel, I have ideas on this but at moment I'm not gonna go into it as have to work it out for myself as its a tricky one, not impossible but tricky as the key switches a number of wires on/off when inserted into ignition, when you turn key to position 1, then 2 & reverse it all switches different wires so I have to 1st find a trigger then work out a wiring circuit to make sure the other circuits become live aswell.

But to add to this I also have to work out how to make sure the car is fully secured aswell as I dont want the car open to starts etc.

Dont worry I'm sure we can work it out somehow, also gotta see what distance the key can be away from the barrel aswell to start the car.
 
Had to sit down last night & draw the damn schematic of the wiring to work out where to stick the diodes as mind was so messed with thoughts of wires, lol.

Anyway diodes need to go as follows:

One needs to be placed on the red wire just literally after the barrel plug before the start button wire connection & it needs to allow current to pass away from the barrel so it blocks any current from going back into the barrel when start button is used.

2nd needs to be placed on the new wire from the start button before it connects to the red wire allowing current away from the start button, so it blocks any current going back down into the start button if you use the key to start the car.

As far as I can tell the wires dont use any reverse polarity so the diode shouldnt cause any issues atall, I will obtain some, test & update the post but I cant see why they would be used for anything but power.

For longevity of the parts & no problems in future I think its better to use the diodes & a fuse inline TBH & no harm done by them anyway, just protects the start button pcb from any shorts etc from say if you did a silly thing like start button press & key turn at same time on those mornings u arent fully awake.

I have of course been using mine with no diodes & hasnt thrown any faults but that doesnt mean it wont, better to make the car think the same circuits are in place than risk having to take trims etc all of again.

I also toyed with the idea of sticking a relay on the yellow wire feed to start button triggered by the barrel start, so when the key was used to start the car it shut of the yellow power feed to the start button aswell so you have protection on the yellow feed into start button & also a diode blocking incoming power on the other wire to start button, so no unneccessary current went to the start button at all unless you pressed the button.

I'll think about that one, might just build a pcb with wires then sell it to everyone, lol, lol.
 
start button finished :yahoo: .... next step go even further back in time and fit a starting handle in the front bumper :think: . or try the best way just put key in and twist:icon_thumright: .. apologies but I really dont see the need for a button unless you have some sort of keyless start system
 
Well glad someone does.

I'm gonna work on a full closure system aswell soon, as I had wired into my S3 of a single click of the existing alarm & keys, will also try to incorporate the mirrors as my S3 had, closed mirrors, windows, roof all on one click, mirrors opened when I unlocked aswell, very ***** mod, lol, lol, think convenience module will be place to do that circuit.
 
Who said we needed it, its just something to see if can be done,thats why we call them Mods, if we took that approach in life nothing would ever progress as we would all be happy with our wind up cars, infact we'd still be neanderthal man, then again from what you see these days in life, some still are, lol, lol.

So treble what have you done to your car?
 
washed it :icon_thumright:.
I understand what you are saying but fitting a button because you can isn't progress.
 
nigelhobden said:
Ok, now parking sensors & S3 kit maybe, you got parking sensors, if so do they mute radio etc & show you in DIS anything or just beeps from rear of car & radio remains running?

Cause audi do the after market version which is the ridiculously expensive same one as you get on fleabay for £30 but they charge £200, I thought the proper CAN version was fully integrated into car on factory installed so mutes radio etc.
Click to expand...

I have the Audi factory fit parking sensors and can confirm they only beep on proximity, show noting on the DIS and do NOT mute the radio.

On the new S3 you can select from a number of different noises they emit and volume so that covers the radio issue!
 
First of all if you had read it through fella, you would see I only fitted cause I sold my S4 B6 gas guzzler which I was gonna fit in but didnt bother, so had it spare so why not see if it fits the A3/S3.

2nd its progress for us on the forum, as it helps people understand the electronics/electrics of the ignition should a fault arise or part needs changing etc, it helps towards other causes & fault finding, so its not a pointless job.

Think outside of the box fella & you will see the wider picture, this mod helps us to maybe come up with a keyless mod, maybe not but at least we know how these things work now.

I assume you have done at least one mod(modification) a remap maybe which you then have to ask, why do I need to make my car go faster if it works already & get me from A to B, cause you maybe liked the extra power, maybe someone likes the start button novelty factor, its same thing just different result.

Its everyone to there own, you dont need/want it, others do.

For me it was a learning lesson so I understood the electrics better for other projects I have on my mind & along the way it helps the others that want to do the mod anyway.

But I dont begrudge anyone with an opinion as this is a forum afterall.
 
JamS3 said:
I have the Audi factory fit parking sensors and can confirm they only beep on proximity, show noting on the DIS and do NOT mute the radio.

On the new S3 you can select from a number of different noises they emit and volume so that covers the radio issue!
Click to expand...

Ah really, oh **** kinda makes me think thats a bit pants, lol, was looking forward to a long drawn out wiring job, lol, but as long as it acheives the right thing then who cares huh.

OK so it works ok no issues, I would prefer it muted the radio as would make sense a CAN signal to mute.

Ah actually that gives me an idea, telephone mute maybe can be used to send a mute signal when reverse is selected, urmmm another wiring job to consider, I'll update you on that one.

You say the new S3 just been released has that new style sensors system, do you know if that mutes the radio?

Thanks in advance.

Nigel.
 
nigelhobden said:
Ah really, oh **** kinda makes me think thats a bit pants, lol, was looking forward to a long drawn out wiring job, lol, but as long as it acheives the right thing then who cares huh.

OK so it works ok no issues, I would prefer it muted the radio as would make sense a CAN signal to mute.

Ah actually that gives me an idea, telephone mute maybe can be used to send a mute signal when reverse is selected, urmmm another wiring job to consider, I'll update you on that one.

You say the new S3 just been released has that new style sensors system, do you know if that mutes the radio?

Thanks in advance.

Nigel.
Click to expand...

I know Parking System Plus is available on the new S3 which is front and rear sensors but dont think it shows the little display on the DIS like the A/S5 showing a range to impact!

I would hazard a guess it will be the same as the current S3 with just the beeps sounding over the radio volume.
 
Sorry just to clarify & just so I'm not being thick, are you saying the beeps/noise the sensing system outputs is coming from the rns-e system/speakers & does as the nav & actually is over the existing sound out of the speakers or its a seperate buzzer at rear of car?

Cause if its in RNS-e then thats good enough for me cause there aftermarket one is seperate buzzer.

Thanks.

Nigel.
 
I just checked with dirk over on navplus as to which signal mute requires to work & I think my mute idea can be easily sorted, all have to do is wire in a relay of say the reverse light which sends a ground signal to the mute pin on the rns & voila mute radio while reversing, love ittttttttttt.
 
nigelhobden said:
I just checked with dirk over on navplus as to which signal mute requires to work & I think my mute idea can be easily sorted, all have to do is wire in a relay of say the reverse light which sends a ground signal to the mute pin on the rns & voila mute radio while reversing, love ittttttttttt.
Click to expand...

Pin C2 on the back of the RNS-e should get you a reverse signal. It is for the reverse camera.
 
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